Currently, angioplasty balloons are used to open calcified lesions in the wall of an artery. However, as an angioplasty balloon is inflated to expand the lesion in the vascular wall, the inflation pressure stores a tremendous amount of energy in the balloon until the calcified lesion breaks or cracks. That stored energy is then released and may stress and injure the wall of the blood vessel.
Electrohydraulic lithotripsy has been typically used for breaking calcified deposits or “stones” in the urinary or biliary track. Recent work by the assignee shows that lithotripsy electrodes may similarly be useful for breaking calcified plaques in the wall of a vascular structure. Shockwaves generated by lithotripsy electrodes may be used to controllably fracture a calcified lesion to help prevent sudden stress and injury to the vessel or valve wall when it is dilated using a balloon. A method and system for treating stenotic or calcified vessels is described in co-pending U.S. application Ser. No. 12/482,995, filed Jun. 11, 2009. A method and system for treating stenotic or calcified aortic valves is described in co-pending U.S. application Ser. No. 13/534,658, filed Jun. 27, 2012. As described in those applications, a balloon is placed adjacent leaflets of a valve to be treated and is inflatable with a liquid. Within the balloon is a shock wave generator that produces shock waves that propagate through the liquid and impinge upon the valve. The impinging shock waves soften, break and/or loosen the calcified regions for removal or displacement to open the valve or enlarge the valve opening. Additional improved lithotripsy or shockwave electrodes that can readily access and treat various locations in the vasculature for angioplasty and/or valvuloplasty procedures may be desirable.